Hybrid two-phase turbine

ABSTRACT

In a rotary turbine having inlets for mixtures of gas and liquid, and a rotary shaft, the combination comprising a separator to receive the mixture of gas and liquid, and to separate the mixture into a stream of gas and a stream of liquid; first structure to receive the stream of gas for generating torque exerted on the shaft; the separator including a rotating surface to receive the stream of liquid to form a liquid layer, and for generating torque exerted on the shaft; there being generally radial outflow passages for the separated liquid stream, and liquid nozzles terminating liquid outflow passages to pass the liquid stream and to convert the induced pressures of the radial outflow of the liquid to velocity of liquid jets, and to convert the reaction forces of the liquid jets to shaft power. Gas nozzles may be provided to receive the separated gas stream which is centrifugally pressurized and expanded through the gas nozzles to produce gas jets directed to produce torque acting on the shaft.

BACKGROUND OF THE INVENTION

This application is a continuation-in-part of U.S. Ser. No. 07/878,605,filed May 5, 1992, now U.S. Pat. No. 5,385,446.

This invention relates generally to method and apparatus for convertingenergy in a two-phase (liquid and gas) fluid jet into mechanical power,as for example is delivered by a rotating turbine shaft. The liquid andgas may be two separate chemical components or may be the vapor andliquid phase of a single chemical component.

In the past, turbine equipment has been built to handle conversion ofgas-phase energy or liquid-phase energy into shaft power. Otherapproaches have been attempted to convert the energy of both phases;however, problems then developed, including erosion, corrosion, and/orconsiderably lower efficiency. For example, a rotating separator hasbeen employed to separate the liquid phase for conversion of kineticenergy of that phase into useful shaft power. However, the kineticenergy of the gas phase was dissipated.

In another example, a separator was not used, and the two-phase jet wasdirectly impinged on moving turbine blades. Here again, kinetic energyof the gas phase was undesirably dissipated, and for high jetvelocities, enhanced corrosion and erosion of the blades tended tooccur.

Flash geothermal systems and some other processes dissipate the energyof two-phase flow, separate the gas, and then pass the gas through agas-phase turbine. This approach wastes most of the available energy ofthe two-phase flow. (In a single component, two-phase system, such assteam and water, the dissipated energy makes heat which producesadditional gas, which can produce some additional power in the gas-phaseturbine; however, it is much less than the available energy of thetwo-phase flow.) This process wastes available energy in the two-phaseflow.

There is need for improved means to convert both the gas energy and theliquid energy in a two-phase flow to useful power, whereby aconsiderable improvement in efficiency can be realized. For example, ifthe two-phase flow from a typical geothermal well is flashed and thesteam is separated and used in a steam turbine, a total of 12,951 kWwould be generated. If a suitable two-phase device is used to convertthe liquid kinetic energy resulting from a two-phase expansion, a totalof 15,014 kW would be generated by the device and a steam turbine,yielding a power increase of 16%.

SUMMARY OF THE INVENTION

It is a major object of the invention to provide improved method andapparatus meeting the above need, and including power generation fromboth liquid and gas phases.

Basically, power generation from a two-phase jet is achieved by aseparation of the two-phase jet into gas and liquid streams for use in arotating structure, so as to preserve most of the kinetic energy of theseparated streams. The structure provides the means to separatelyconvert the kinetic energy and enthalpy of the separated gas and of theseparated liquid into shaft power.

In its apparatus aspects, rotary turbine equipment utilizing theinvention has inlet means for mixtures of gas and liquid, and rotaryshaft means, and

a) separator means to receive the mixture of gas and liquid in a stream,and to separate the mixture into a stream of gas and at a stream ofliquid,

b) first means to receive the stream of gas for generating torqueexerted on the shaft means, and

c) second means to receive the stream of liquid for generating torqueexerted on the shaft means,

d) whereby the first and second means separately operate to generateshaft power.

As will appear, the stream of liquid has an associated velocity head,and the above second means typically may include a diffuser to receivethe stream of liquid and to convert the velocity head thereof topressure. Also, the mix of liquid and gas has an associated pressure andthermal energy, and the separator means typically may include atwo-phase nozzle means for flowing the gas and liquid, and forconverting the mixture pressure and thermal energy into kinetic energyand directing the streams of gas and liquid to the first and secondmeans, respectively. That nozzle may have an adjustable area throat, aswill be seen.

In addition, the above referenced second means may typically andadvantageously include a surface rotating about an axis defined by theshaft means and at a velocity equal to or lower than the velocity of theseparated stream of liquid, for receiving impingement of the stream ofliquid to convert a portion of the kinetic energy thereof to shaft meansenergy by production of frictional forces formed by slowing the liquidstream to a velocity close to or equal to the velocity of theimpingement surface.

Other objects include incorporation in the above referenced first meansof radial inflow blades to receive impingement of the stream of gas andto convert the associated kinetic energy and enthalpy of the gas toshaft means energy; of axial flow blades to receive impingement of thestream of gas and to convert the associated kinetic energy and enthalpyof the gas into shaft means energy; and of radial outflow blades toreceive impingement of the stream of gas and to convert the associatedkinetic energy and enthalpy of the gas to shaft means energy. Sheardiscs may also be provided, as will be seen. Axial flow nozzles andaxial flow blades may be provided on the shaft means to convertremaining kinetic energy and enthalpy of the separated gas to shaftpower.

A further object includes incorporation in the separation means ofradial passages for the separated liquid stream, and liquid nozzlesterminating the outflow passages to pass the liquid stream and toconvert the induced pressures of the radial outflow of the liquid tovelocity of liquid jets, to convert the reaction forces of the liquidjets to shaft power.

Yet another object includes incorporation in the separation means of agas-liquid separator surface or surfaces, a diffuser being located inthe path of the separated liquid, the diffuser having a bleed of highpressure separated liquid directed to the separating surface to controlthe centrifugal liquid level of the separated liquid in the turbine, tominimize gas ingestion by the diffuser.

Additional objects include the provision of

a) separator means to receive the mixture of gas and liquid, and toseparate the mixture into a stream of gas and a stream of liquid,

b) first means to receive the stream of gas for generating torqueexerted on the shaft means,

c) said separator means including a rotating surface to receive thestream of liquid to form a liquid layer, and for generating torqueexerted on the shaft means,

d) there being generally radial outflow passages for the separatedliquid stream, and liquid nozzles terminating said outflow passages topass the liquid stream and to convert the induced pressures of theradial outflow of said liquid to velocity of liquid jets, to convert thereaction forces of said liquid jets to shaft power.

Further, the separator means forms at least one lip adjacent saidsurface to block the liquid layer from flow past the lip, the outflowpassages communicating with the liquid layer proximate the lip toreceive liquid from the liquid layer centrifugally urged toward thepassages.

The separator means also typically forms at least one gas escape slot orslots spaced radially inwardly relative to said lip, there being gasnozzles to receive the gas flow relatively outwardly from the escapeslot or slots toward the gas nozzles, the gas flow subjected tocentrifugal force to increase the gas pressure, the gas then expandingthrough the gas nozzles to produce gas jets directed to produce torqueacting on said shaft means.

Also, multiple of the liquid and gas nozzles as referred to mayalternate about the shaft axis, for dynamic and torque productionbalance, and may be directed counterclockwise.

These and other objects and advantages of the invention, as well as thedetails of an illustrative embodiment, will be more fully understoodfrom the following specification and drawings, in which:

DRAWING DESCRIPTION

FIG. 1 is a diagrammatic view of structure to accomplish conversion ofkinetic energy of both gas and liquid phases, of a two-phase jet, intorotary shaft power output;

FIG. 2 is a section taken through actual turbine structure showingtwo-phase nozzle structure, separator means, blades, and otherstructure;

FIG. 2a is an enlarged fragmentary view showing two-phase nozzle meansand separator structure;

FIG. 3 is an end view showing rectilinear, two-phase nozzles disposed inan annular configuration;

FIG. 4 is a schematic showing of a liquid reaction turbine;

FIG. 5 is a view like FIG. 2 but showing integration of liquid reactionmeans into actual turbine structure;

FIG. 5a is an enlarged fragmentary view showing turbine two-phase nozzlemeans, phase separator structure, and a liquid reaction passage andnozzle;

FIG. 6 is a view like FIG. 4 showing radial outflow gas passages as wellas liquid passages;

FIG. 6a is a section taken on lines 6a--6a of FIG. 6;

FIG. 6b is a section taken on lines 6b--6b of FIG. 6;

FIG. 7 is a section taken through an actual turbine structure whereinremaining enthalpy of the gas leaving separator structure of the typeshown in FIGS. 1, 2, 4, 5, and 6 is converted to shaft power by usingaxial flow blades and nozzles;

FIG. 7a is an enlarged section showing parts of FIG. 7;

FIG. 8 is a flow diagram showing a steam engine that can be operatedusing wet steam;

FIG. 9 is a flow diagram showing use of a two-phase turbine in a doubleflash geothermal power plant;

FIGS. 10(a)-10(e) are fragmentary cross sections showing adjustablenozzle throat structural details;

FIGS. 11(a)-11(c) are fragmentary cross sections showing diffuserdetails;

FIG. 12 is a schematic view showing further detail of a liquid reactionturbine;

FIG. 13 is a section taken on lines 13--13 of FIG. 12;

FIG. 14 is an axial view showing inlet nozzles;

FIG. 15 is an enlarged view showing a typical inlet nozzle in detail.

DETAILED DESCRIPTION

FIG. 1 shows a structure to accomplish the conversion of the kineticenergy of both the gas phase and the liquid phase of a two-phase jet.The two-phase jet is directed in a generally tangential direction ordirections 10 to a rotating surface 11 facing radially inwardly towardaxis 12, surface 11 providing a rotor structure 13. Under the action ofcentrifugal forces resulting from the rotating surface, the liquidseparates from the gas. The separated liquid layer 14 slows from itstangential velocity (indicated by arrow 15) at impingement to thetangential velocity of the rotating surface (indicated by arrow 15a).The liquid is decelerated to the tangential velocity by friction forces.The resulting drag forces on the rotating surface produce a torque andhence power transfer to the rotating structure 13. Power is produced atthe single shaft 16 by this liquid energy conversion. Shaft 16 carriesrotor 13.

The separated gas flows in a generally tangential direction in anannulus formed by the liquid layer 14 and a radial inflow gas bladestructure 17. The gas enters the radial inflow blading and is directedradially inwardly (see arrow 18) by the blades. The radial momentumtransferred by the gas to the blading by the gas, as its tangentialvelocity is decreased, produces a torque on the blade structure 17 andthe rotating structure 13. Such torque produces additional power at thesingle shaft 16.

The separated layer of liquid is removed by a scoop 20. The scoop may becontoured with an area profile to slow the liquid tangential velocity15a to a lower velocity, recovering residual kinetic energy as pressure.

The separated gas leaves the radial inflow blades in a generally axialdirection 21. Residual enthalpy can be converted to shaft power in aseparate gas phase turbine or by the addition of blading to the shaft16.

The device shown utilizes the single rotating structure to:

a) separate gas from liquid efficiently,

b) generate power from the liquid phase,

c) generate power from the gas phase,

d) pump the separated liquid to a higher pressure.

The device accomplishes the above unexpected combination of items whileavoiding erosion of the liquid conversion surfaces, which are protectedby the liquid film. The device also accomplishes the unexpectedcombination of items while avoiding erosion of the gas blades byseparating the liquid from the gas by the high centrifugal forces of therotating surface.

Other means to convert two-phase flow energy to useful power are shownin FIG. 2. A two-phase flow at generally high pressure 24 enters atwo-phase nozzle structure inlet 25. The pressure of the flow is loweredin a two-phase nozzle passage 26 in non-rotating body 27. The loweringof pressure causes the two-phase mixture to be accelerated to agenerally higher velocity.

The resulting two-phase jet 27b (see broken lines and arrow 27a)impinges in a generally tangential direction onto a rotating surface 28on rotor 28a integral with shaft 29. The large centrifugal forcesproduced by the rotating surface result in separation of the gas phasefrom the liquid phase and in the formation of liquid layer 30 on therotating surface 28.

FIG. 2 shows a cross section of the nozzle and device. The directions ofthe two-phase flow and separated liquid correspond to those shown in thedrawing of FIG. 1.

The separated liquid film is slowed to the velocity of the rotatingsurface 18 by friction. The resulting drag forces produce a torque andpower transfer to the single shaft 29. The separated gas 32 flowsthrough axial steam blades at 31, on rotor 28a. See gas flow arrow 32,and also see FIG. 2a. The change in direction, caused by the blades,results in a force on the blades which also produces a torque and powertransfer to the single shaft 29. A cylindrical guide 33 is provided todirect the separated gas to the blades, to minimize entrainment ofsurrounding stagnate gas. The guide may have radial vanes 34 to furtherminimize entrainment. After leaving the blades 31, the gas leaves theturbine through a port 35.

After the liquid is slowed to the velocity of the rotating surface, itflows through axial transfer holes 36 in 28a to the opposite side of therotor disc 28b. The separated liquid is collected by a scoop 36a fromthis side of the rotor disc, the scoop penetrating liquid layer 30. Thescoop may be contoured to efficiently slow the residual velocity of theliquid, generating pressure in the separated liquid.

The open volume 37 inside the casing 20a is filled with gas. The shaftseals 38, bearings 39, and thrust bearings 40 are conventional gas dutycomponents. Casing structure appears at 41 and 42. If the device is usedto pressurize a corrosive liquid, such as geothermal brine, thereliability of pumping is much greater than a normal pump. Thisunexpected result occurs because the seals and bearings are only exposedto clean gas at 37, instead of the corrosive liquid.

The two-phase nozzles 26 spaced about shaft 29 and used for acceleratingtwo-phase flow for power conversion in the turbine may have axisymmetricor rectilinear design.

FIG. 3 shows a two-phase nozzle which improves the performance ofaxisymmetric geometries by having a rectilinear cross section normal tothe direction of flow.

Flow 124 entering the two-phase nozzle 126 is at relatively highpressure. The flow is accelerated to higher velocities as it flows tothe nozzle exits from nozzle ring 127 corresponding to ring 27 in FIG.2. Side walls 129 are provided to guide the flow so that it leaves thelike nozzles at the desired angle α to the plane perpendicular to theaxis of the turbine to which the flow is introduced.

The advantage of the two-dimensional geometry is that the height 130 ofthe nozzle can be minimized. The momentum energy loss due to a finitenozzle height is:

    LOSS=1.0-(D-h).sup.2 /D.sup.2                              (1)

Where:

D=Diameter of separating surface

h=Height of nozzle exit

For an axisymmetric nozzle, the exit area is:

    A=(0.785)(d.sup.2)                                         (2)

Where:

d=diameter of axisymmetric nozzle

w=width of two dimensional nozzle

For a two dimensional geometry, the exit area is:

    A=(h)(w)                                                   (3)

For equal areas, the height, h, is given by:

    h=(0.785)(d.sup.2)/(w)                                     (4)

For d=1.0 and w=5, h=0.157, these being units of measurement. Thus, theheight of the two dimensional nozzle exit height is only 0.157 times theheight of the axisymmetric nozzle for this example. If the separatingsurface diameter is 6.0, the loss with an axisymmetric nozzle is 0.3055times the kinetic energy of the two-phase flow leaving the nozzle. Theloss with the two-dimensional nozzle above is only 0.0516 times thekinetic energy.

The nozzles of FIG. 3 can be designed so that all guide vanes and exitstreamlines have a constant angle to the plane perpendicular to the axisof the turbine into which the jet flows. Since the loss of kineticenergy is proportional to 1.0 minus the cosine of that angle e squared,the minimum loss will occur for equal angles.

Other means can be provided to convert the kinetic energy of theseparated liquid into shaft power in conjunction with either of the gasblading concepts shown.

FIG. 4 schematically shows a liquid reaction turbine 50 which can beused. The separated and centrifuged liquid 51 flows onto the rotor 52separating surface 52a at the rotary speed of that surface. Theseparated liquid transfers power to the rotor under the action of thefrictional forces, as described in FIGS. 1 and 2. A passage 53 isprovided in the rotor for the liquid to flow radially outward, at 54.The centrifugal force field resulting from the rotation of theseparating structure causes an increasing pressure in the liquid as itflows outward. At the end of the radial passage, a liquid nozzle 57 isprovided. The liquid accelerates through the nozzle and leaves therotating structure at a relatively high velocity. See arrow 58. Thereaction force from the leaving high velocity liquid jet produces atorque, which is exerted via rotor 52 onto shaft 59 and converted toshaft power. In this regard, the disclosure of U.S. Pat. No. 4,298,311is incorporated herein, by reference.

FIGS. 5 and 5a are cross sections showing the integration of the liquidreaction means into the turbine structure of FIG. 2. A radial passage 61is provided for radial outflow of the separated liquid. The separatedliquid flows radially outward at 62 and is accelerated through a liquidnozzle 63. The jet flows through a narrow passage 64 in annulus 65 onthe turbine casing. The flow passage is configured so that the jetsweeps out any back flow of liquid. The liquid is collected in acollector passage 66 and leaves through a port 67. The reaction forcesfrom the jet leaving the separation structure on 28a at high velocityproduce a torque which is exerted via rotor 28a and is additive to thetorque produced by the liquid drag forces and by the separated gas beingturned by the axial flow blades. The result is that the power producedby all three sources is transmitted by the single shaft 29.

FIGS. 6 through 6b are similar to FIG. 4, but show a two-phase turbinerotor 179 having liquid reaction passages 180 and associated nozzles 181for liquid supplied from separation ring segments 182, to convert theliquid kinetic energy to shaft power. Also, radial outflow gas passages184 and nozzles 185 receive separated gas from ring segment zones 186 toconvert the separated gas kinetic energy and enthalpy to shaft power. Inanother configuration, radial outflow blades may be used instead of thepassages 184 and nozzles 185 to convert the gas kinetic energy to shaftpower.

FIGS. 7 and 7a show a turbine where the remaining enthalpy of the gasleaving a two-phase rotary separator turbine of the types described inFIGS. 1, 2, 4, 5, and 6 is converted to shaft power on the same shaft byadding axial flow gas blades and nozzles. Two-phase flow is introducedto the nozzle at 201. The flow is accelerated in the nozzle 202 to arelatively high velocity. Liquid is separated and decelerated by therotary separator rotor 203, converting the kinetic energy of theseparated liquid to shaft power. The separated steam flows throughradial inflow gas blading 205, converting the kinetic energy and someenthalpy of the separated gas to additional shaft power. The gas leavingthe rotary separator first stage is accelerated in a stationary gasnozzle 206. The relatively high-velocity gas is passed through gasblading 207, attached to the common rotating shaft 209. The gas passesthrough additional gas phase turbine stages, as required, to convert thegas enthalpy to power of the common shaft 209. The gas leaves the gasphase turbine stages 208 at 208a and is exhausted to a condenser orprocess use. The combined turbine has conventional seals 210 andbearings 211 for the gas phase.

The combined geometry, when applied to steam flows, enables wet steam tobe used to generate power directly in a turbine.

FIG. 8 shows a steam engine which can be operated with wet steam. Steamis generated in a heat exchanger or boiler 251. The steam may be dry,moderately wet (for example 70%-80% steam quality) or very wet(saturated water to 70% steam quality). If the steam quality is at therequired value, the two-phase flow 249 may be introduced directly to therotary separator turbine stage 253. If a lower steam quality is requiredthan the steam quality provided by the heat exchanger, water may beinjected at 252 to lower the steam quality. The steam separated andleaving the rotary separator turbine stage passes through the gas phaseturbine stages 254. The power generated by the separated liquid and gasis transmitted from the single shaft 255. Steam leaving the seals at 258and steam leaving the turbine at 257 is condensed in a condenser 259.The condensate is pressurized by a pump 260. The liquid leaving therotary separator stage at 253 can be pressurized by an internaldiffuser. If so, it is routed by valve 291 upstream at 263 of the feedpump 262 and mixes with the condensate. The resulting flow at 264 isrouted to the heat exchanger 251. If required, a part of the return flow264 can be routed at 268 by valve 269 to be mixed with the flow from theheat exchanger.

The following advantages pertain to a wet steam engine compared to adry, saturated steam engine:

1) The wet steam heat exchanger is much smaller than a dry steam heatexchanger. No separator to obtain dry steam is required. The heattransfer coefficients on the steam side are much higher because of therelatively wet steam flow.

2) The steam wetness in the steam stages of the wet steam turbine islower than for a dry, saturated steam turbine having the same inletpressure as the rotary separator turbine stage. This is because therotary separator stage removes the water phase, producing dry, saturatedsteam for the steam turbine stages at a lower pressure than for the dry,saturated steam turbine. The turbine blade efficiency is thereforehigher and the erosion potential is much less. This is a completelyunexpected result of using the rotary separator turbine in conjunctionwith conventional steam turbine blading. It would not be obvious that awet steam turbine would have less erosion potential and a higher bladeefficiency than a turbine to which dry steam was admitted.

3) Because of the increased blade efficiency and the feedwater heatingfrom the separated water, the wet steam engine efficiency is higher thana simple, dry, saturated steam engine at the same maximum temperature.

Another application of the rotary separator turbine is to improve theefficiency of geothermal power plants. FIG. 9 illustrates thisapplication. In a conventional flash steam geothermal plant, two-phaseflow from a geothermal well 301 at a relatively high pressure p₁ ispiped to a flash tank 302. The two-phase flow flashes to a lowerpressure p₂. This isenthalpic lowering of pressure produces additionalsteam, but no power. The steam is separated and flows at 303a to a steamturbine 303, which drives a generator 304, producing electrical power inthe amount of P₁. The steam leaving the steam turbine at 308 iscondensed in a condenser 309, and the condensate is pressurized by apump 310. The separated brine 305 may be pressurized and reinjected intothe ground or it may be piped to a lower pressure flash tank 306 wherethe pressure is lowered, producing additional steam at a pressure of p₃.The lower pressure steam at 307 can be admitted to a low pressure portof the steam turbine to produce additional power (or it can be used forother power-producing purposes, such as driving a turbocompressor).

A rotary separator turbine 314 can be installed in a flow circuitparallel to the two-phase flow line and high pressure flash tank 302.Two-phase flow is routed at 312 by valve 313 through this circuit to thehigh pressure rotary separator turbine 314 (RST). The pressure isreduced in the RST 314 from p₁ to p₂, producing additional steam andpower P₂. The separated steam at p₂ is piped at 315 to the flash tank302, producing identical steam conditions as the conventional flashsystem. The amount of steam is reduced slightly by the energy equivalentof the power generated P₂ by the RST. Isolation valves 313 and 316 areprovided so that the flash steam system and steam turbine can continueto operate even when the RST is shutdown. The separated brine 318 fromthe RST may either be reinjected into the ground or it may be piped to alow pressure RST 319. The brine can be flashed to p₃ in the low pressureRST, producing additional power P₃. The separated low pressure steam ispiped at 330 to the low pressure flash tank 306 at the same conditionsas the conventional flash system. The separated brine can berepressurized by the low pressure RST 319 so that it can be reinjectedat 325 without a pump 324, which reduces the plant auxiliary powerrequirements.

Table 1 shows the power added by the RST to a typical high pressuregeothermal well. A total gain of 16% is obtained after taking intoaccount the small decrease in steam flow and steam turbine power.

                  TABLE 1                                                         ______________________________________                                        p.sub.1 =        939 psia                                                     p.sub.2 =        202 psia                                                     m =              131 lbls                                                     h.sub.1 =        1198.5 Btu/lb                                                P.sub.1 +P.sub.2 =                                                                             15,014 kW                                                    P.sub.flash =    12,951 kW                                                    ______________________________________                                    

where:

p₁ =wellhead pressure

p₂ =steam pressure

m=total flow rate

h₁ =wellhead enthalpy

P₁ +P₂ =total power of two phase turbine and steam turbine

P_(flash) =steam turbine power from flash alone.

The RST can be made to be more flexible and controllable if thetwo-phase nozzle throat area can be varied. FIG. 10 shows one method tovary the throat of a two-dimensional nozzle. A movable plate 351 isprovided at the throat 352 of the nozzle. An actuator 353 is provided tomove the plate in a direction perpendicular to the axis of the RST. Fora set of nozzles around the periphery of the RST, the plate can be acircular segment which is rotated under the action of the actuator. Theplate has teeth 358 which protrude into the nozzle throat passage 356.In the fully open position, the teeth 358 are translated to a positionsuch that the throat passage is wide open. To throttle the flow, theplate is translated so that the teeth block part of the throat passage356. The resulting reduction in area lowers the flow rate through thenozzle. The abrupt change in area produces a high local pressuregradient which atomizes the droplets and can produce a higher nozzleefficiency. Other elements show intake nozzle cap 365, top housing 366,and nozzle inlet 367.

Improvement in the diffuser performance and reduction in noise ispossible if the amount of gas ingested can be reduced. Means toaccomplish this are shown in FIG. 11. Gas ingestion can occur when thesurface of the liquid layer does not fill the diffuser 400 entrance 405.One way to fill the opening is to reduce the size of the opening. Amovable, contoured insert 402 is provided within the diffuser body 401.The insert is attached to a structure 403 with linear gear teeth whichis translated by a gear 404 on a shaft. Translation of the insertresults in enlarging or reducing the size of the diffuser opening. Theinsert is sealed by elastomer or bellows seals. The resulting collectedliquid flow is pressurized and leaves the RST through a pipe 407.

Another method to reduce gas ingestion is to reintroduce a part of thecollected flow into the liquid layer to increase the depth of the layerso that the diffuser opening is more completely filled. Part of the flowcollected is routed through a pipe 409 to a nozzle 410. A jet 411 isproduced, which is directed into the flow 412 on the rotary separatorsurface 413, which faces toward the shaft axis. The recirculating flowincreases the mass flow entering the diffuser opening causing anincrease in flow area. The diffuser inefficiency and the liquid nozzleinefficiency result in a velocity of the liquid jet 411, which is lowerthan the velocity of the liquid layer 412. This effect also increasesthe flow area.

In the form of the invention seen in FIGS. 12-15 two phase nozzles 201are used to accelerate a gas-liquid mixture 200, forming a high velocitytwo-phase jet 202. The two-phase jet impinges tangentially onto arotating separation surface 204 on a separator 204a forming a liquidlayer 203, and a gas flow 207. Separator 204a rotates about axis 240 ofshaft 241.

The liquid (such as water) enters a slot or hole 213 in 204a and whichis radially outward relative to the radius of lip or dam 212, whichrestrains the liquid layer. The liquid flows radially outward at lowvelocity through liquid passages 205, in the rotor 214.

The centrifugal force field causes an increase in pressure as the liquidflows outward. At the exit of the passages 205 the liquid is acceleratedthrough a liquid nozzle 210, to a lower pressure forming a jet 206. Thereaction force from the jet, produces a torque on the shaft 241. Nozzles210 are directed counterclockwise as shown.

The separated gas flow 207, flows into a gas slot or hole 215 in 204a,which is radially inward (i.e. toward axis 240) from the radius to thelip 212 that restrains the liquid. Because the separated liquid as atlayer 203 is forced by the centrifugal force field to be radiallyoutward of the gas slots 215, liquid is precluded from entering with thegas into the gas slots 215.

The gas entering a slot 215 flows radially outward through the gaspassages 208 in 204a at low velocity. The centrifugal force field causesan increase in gas pressure as the gas flows outward.

At the exit of the passages 208, the gas is expanded through gas nozzles209 to a lower pressure, thereby producing high velocity gas jets 216.The reaction force from the jets also produces a torque on the shaft241. As shown, the gas nozzles 209 are also directed counterclockwise.Nozzles 209 alternate with nozzles 210 for dynamic balance, and torqueproduction balance, about axis 240.

In FIG. 12, gas collection or reception passage zones 215a alternatewith liquid reception or collection holes 213 associated with the liquidring or layer 203; as schematically shown. As explained above, the holes215 are at a lesser radius relative to holes 213.

Two-phase nozzles 201 are fixedly carried by non-rotary structure 199.

I claim:
 1. In a rotary turbine having inlet means for mixtures of gasand liquid, and rotary shaft means, the combination comprisinga)separator means to receive the mixture of gas and liquid, and toseparate the mixture into a stream of gas and a stream of liquid, b)first means to receive the stream of gas for generating torque exertedon the shaft means, c) said separator means including a rotating surfaceto receive the stream of liquid to form a liquid layer, and forgenerating torque exerted on the shaft means, d) there being generallyradial outflow passages for the separated liquid stream, and liquidnozzles terminating said outflow passages to pass the liquid stream andto convert the induced pressures of the radial outflow of said liquid tovelocity of liquid jets, to convert the reaction forces of said liquidjets to shaft power, e) said liquid nozzles being spaced about an axisdefined by said shaft means.
 2. The combination of claim 1 includingtwo-phase nozzles positioned to direct said mixture toward said rotatingsurface.
 3. The combination of claim 2 wherein said two-phase nozzlesare spaced about said axis defined by said shaft means.
 4. Thecombination of claim 2 wherein said separator means forms at least onelip adjacent said surface to block said liquid layer from flow past thelip, said outflow passages located to receive liquid from said layercentrifugally urged toward said passages.
 5. The combination of claim 4wherein said separator means forms at least one gas escape slot spacedradially inwardly relative to said lip, there being gas nozzles toreceive the gas flow relatively outwardly from said escape slot towardsaid gas nozzles, the gas flow subjected to centrifugal force toincrease the gas pressure, the gas then expanding through the gasnozzles to produce gas jets directed to produce torque acting on saidshaft means.
 6. The combination of claim 5 wherein there are multiplesof said liquid nozzles and multiple of said gas nozzles.
 7. Thecombination of claim 6 wherein said gas and liquid nozzles alternate,about the axis defined by said shaft means.
 8. The combination of claim8 wherein all of said nozzles are directed counterclockwise.